Pneumatic piano.



W. G. BETZ.

PNEUMATIC PIANO.

. APPLICATION FILED ITBB.6, 1911.

Patented J an. 9, 1912.

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INVENZTOR. Wllimm G. B 1;

WITNESSES: @m 7% ATTORNEY.

W. G. BETZ.

PNEUMATIC PIANO.

APPLICATION FILED FEB. s, 1911,

1,014,364, Patented Jan.9, 1912.

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WITNESSE ATTORNEY.

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UNITED STATES PATENT OFFICE.

WILLIAM G. BETZ, OF CHICAGO HEIGHTS, ILLINOIS, ASSIGNOR TO STEGER & SONSPIANO MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION.

PNEUMATIC PIANO.

Application filed February 6, 1911.

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, IVILLIAM G. Bn'rz, a citizen of the United States,and a resident of Chicago Heights, county of Cook, and State ofIllinois, have invented a certain useful Pneumatic Piano; and I dohereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawings.

The object of this invention is to provide an improved means for lockingthe ordinary finger keys of a player piano so that they will not movewhile the piano is being pneumatically operated.

The nature of the invention will be understood from the accompanyingdrawings and the following description and claims.

In the drawings Figure l is a front elevation of the lower part of aplayer piano, the front plate of the lower left hand corner portionbeing broken away. Fig. 2 is a vertical section on the line 22 of Fig. 3longitudinally of the piano through the finger keys and adjacent parts,showing the key lock in looking position by full lines and in unlockingposition by dotted lines. Fig. 3 is a vertical transverse sectionthrough the lower portion of the piano on the line 33 of Fig. 1. Fig. 4cis a section on the line 4.4: of Fig. 3.

In the drawings represents the front wall of the piano casing, 11 thekey board, and 12 the ordinary finger keys. Beneath the forward portionof the ordinary finger keys a locking bar 15 is located, as shown inFig. 2, and extends entirely across the piano longitudinally, and ispivoted at each end to a link 16 which is pivoted to the key board 11within the recesses 17, and about midway said locking bar 15 is pivotedon the upper end of a lever 18 which is fulcrumed at 19 to the key board11 in an opening 20 which extends through the key board so that saidlever projects below the key board, and by this means the locking leveris moved from the locking to the unlocking position, that is, from thefull line to the dotted line position shown in Fig. 2. The locking baris preferably lined with felt on its upper side and it is actuated ormoved into locking position against the under side and the keys 12 by aretractile spring 21 which extends from one end of the bar 15 to the end22 of the casing. The lever 18 is actuated by a link 24, see

Fig. 4, which extends to the bell crank lever 25 fulcrumed by a pin 26to the underside of the key board 11 and with which a rod 27 is pivoted.This rod 27 is adjustably coupled with a rod 28 by a coupling 29 andextends loosely through a hole, not shown, in an arm 30 of the bellows31 which is the main air reservoir and in the rear portion of the piano.Said reservoir is in communication through the opening 32 with anairchamber 33 which extends longitudinally of the piano and from whichair is exhausted through a pipe 34: by the bellows 35 which is actuatedby the pedal 36, and intermediate means which constitute no part of thisinvention, as any arrangement may be employed for exhausting the airfrom the air chamber 33. The bellows 35 is a double bellows having astationary part 37 mounted on supports 38 and the upper bellows isactuated by a rod 39 connected with a bell crank lever a2 fulcrumed atll which has an extension arm 40. The lower bellows is operated directlyby the lever 42.

A bar 43 connects the pedal with said lever 42. The lower end of thepedal is pivoted to a bar 44 which is fulcrumed at 15 to enable thepedal to be folded into the piano casing, but this constitutes no partof the present invention.

When the piano is not pneumatically operated, the reservoir 31 will beexpanded in the position shown in Fig. 3, and, therefore, will actuatethe bell crank lever 25 and hold it in its dotted line position, asshown in Fig. 4E, and that will hold the lever 18, see Fig. 2, in itsdotted line position, whereby the locking bar is kept down or away fromthe finger keys 12. This may be said to be the normal position of thepiano and then it can be played by the fingers in the ordinary way.When, however, the piano is pneumatically operated the pedals 36 willcollapse the reservoir or bellows 31 and, thereby release the spring 21,see Fig. 2. That is, it will draw the locking bar up into lockingposition and while the piano is pneumatically operated, the finger keyswill not move.

I claim as my invention:

A pneumatic player piano including finger keys, a key board, a lockingbar under the forward portion of the finger keys, means for moving thelocking bar to a looking position, a lever connected with the lockingbar and extending through and fulcrumed in the key board for moving thelocking bar to an unlocking position, a bell crank lever fulcrumed tothe underside of the key board and connected to said unlocking lever, abellows provided with an arm extending therefrom having an opening in ita rod extending from the bell crank lever through said arm and enlargedbeyond the arm, and means for exhausting air from the bellows, wherebywhen the bellows col lapses it will permit the locking bar to move intolocking position and when the bellows expands it will move the lockingbar to an unlocking position.

In witness whereof, I have hereunto aflixed my signature in the presenceof the witnesses herein named.

WILLIAM G. BETZ. lVitnesses H. C. VVEHLAN,

OLGA PETERSON.

Copies of this patent may be obtained for five cents each, byaddressing" the Commissioner of Patents, Washington, D. G.

